Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 10 of 10

Full-Text Articles in Physical Sciences and Mathematics

Patterns Of Age-0 Gizzard Shad Abundance And Food Habits In A Nebraska Irrigation Reservoir, Christopher L. Sullivan, Casey W. Schoenebeck, Keith D. Koupal, W. Wyatt Hoback, Brian C. Peterson Dec 2011

Patterns Of Age-0 Gizzard Shad Abundance And Food Habits In A Nebraska Irrigation Reservoir, Christopher L. Sullivan, Casey W. Schoenebeck, Keith D. Koupal, W. Wyatt Hoback, Brian C. Peterson

The Prairie Naturalist

Gizzard shad (Dorosoma cepedianum) are prolific spawners that can influence reservoir communities. Larval gizzard shad may compete with larval recreational fish for zooplankton resources. Therefore, it is necessary to determine larval gizzard shad dynamics and food habits to better understand their potential for competition with larval recreational fish. Our study examined age-0 gizzard shad abundance in Harlan County Reservoir during late spring/summer from 2002–2010 and food habits and prey electivity of age-0 gizzard shad during late spring/summer 2008 and 2009. The annual peak age-0 gizzard shad density 3 from 2002–2010 ranged from 50 to 380/100 m , which …


Habitat Use And Abundance Patterns Of Sandhill Cranes In The Central Platte River Valley, Nebraska, 2003–2010, Todd Joseph Buckley Nov 2011

Habitat Use And Abundance Patterns Of Sandhill Cranes In The Central Platte River Valley, Nebraska, 2003–2010, Todd Joseph Buckley

School of Natural Resources: Dissertations, Theses, and Student Research

The Central Platte River Valley (CPRV) in Nebraska is an important spring stopover area for the midcontinent population of sandhill cranes. Alterations to crop rotation and loss habitat in the CPRV pose a risk to the population. Personnel drove designated routes in the CPRV from 2003–2010 to record the presence of cranes in agricultural fields and estimate abundance. I developed and evaluated models to predict habitat use and flock sizes. Alfalfa was predicted to receive the highest use followed by corn, soybeans, winter wheat, grassland, and shrubland. Use of all habitats and flock size increased as field area increased. Flock …


Breeding Fidelity And Landscape Effects On Distribution Of Mallards And Duck Broods In The Nebraska Sandhills, Zachary J. Cunningham Aug 2011

Breeding Fidelity And Landscape Effects On Distribution Of Mallards And Duck Broods In The Nebraska Sandhills, Zachary J. Cunningham

School of Natural Resources: Dissertations, Theses, and Student Research

I investigated aspects of mallard (Anas platyrhnchos) breeding ecology in the Nebraska Sandhills during 2007-2008. Previous work in this region suggests that nest success is low for a large area of intact grassland such as the Sandhills. My goal was to conduct a local-scale examination of age distribution and return rates of mallards, and a large-scale examination of brood distribution in the Sandhills region as a whole. This information will help explain factors contributing to the low nest success previously observed, determine relationships between landscape composition and spatial distribution of waterfowl in the Sandhills, and predict productivity and …


Spatial Accuracy Of Climate Networks In Nebraska, Andrea J. Coop Jul 2011

Spatial Accuracy Of Climate Networks In Nebraska, Andrea J. Coop

School of Natural Resources: Dissertations, Theses, and Student Research

Climate data has become increasingly scrutinized for its accuracy because of the need for reliable predictions about climate change. The U.S. has taken great strides to keep up with the demand for accurate climate data. Over the last thirty years, vast improvements to instrumentation, data collection, and station siting have created more accurate data records. This study is to explore the accuracy of existing networks. This study analyzes three climate networks used in Nebraska: the U.S. Historical Climatology Network (HCN), the Automated Weather Data Network (AWDN), and the newest network, the U.S. Climate Reference Network (CRN). Each of these networks …


Late Holocene History Of Dune Activity Along The Elkhorn River In Northeastern Nebraska, Rebecca A. Young Jul 2011

Late Holocene History Of Dune Activity Along The Elkhorn River In Northeastern Nebraska, Rebecca A. Young

School of Natural Resources: Dissertations, Theses, and Student Research

The Nebraska Sand Hills have been an important study area for dune activation and the nature of prehistoric drought events in the Great Plains. However, little has been done to understand the impact of these droughts to smaller dune fields along the eastern margin of the Great Plains. This study focuses on the Stanton dune field which is found about 145 km east of the Sand Hills along the southern edge of the Elkhorn River valley in northeastern Nebraska. With a wetter and slightly cooler climate regime than that of the Nebraska Sand Hills and most other central Great Plains …


Natural Selection And Age-Related Variation In Morphology Of A Colonial Bird, Mary Bomberger Brown May 2011

Natural Selection And Age-Related Variation In Morphology Of A Colonial Bird, Mary Bomberger Brown

School of Natural Resources: Dissertations, Theses, and Student Research

In May 1996, inclement weather led to the deaths of thousands of Cliff Swallows (Petrochelidon pyrrhonota) in Nebraska. Survivors had larger skeletons, shorter wings and tails, and less wing asymmetry than non-survivors. This population was followed for 10 years to study 1) whether natural selection events result in permanent microevolutionary changes, 2) if variation in climate affects the development of morphological traits, and 3) if morphological traits vary systematically with age.

Patterns in morphology exhibited by swallows following the selection event were studied by measuring yearling birds. Wing and middle tail lengths decreased, beak length and width increased, …


Nest Survival Of Long-Billed Curlew In Nebraska, Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen Jan 2011

Nest Survival Of Long-Billed Curlew In Nebraska, Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen

School of Natural Resources: Faculty Publications

Long-billed Curlew Numenius americanus is an imperiled shorebird of western North America. Populations have declined dramatically in the last 150 years from the conversion of prairie to agriculture and it is now listed as a “Tier I at-risk” species in Nebraska. We undertook a 3-year project (2008–2010) to study the nest survival of Long-billed Curlews in Nebraska. We measured vegetation characteristics at each nest site (n = 14 nests) on two different spatial scales and used program MARK to model nest survival as a function of multiple covariates. Apparent nest survival was 29% (n = 4 successful nests) and our …


Nebraska's Tern And Plover Conservation Partnership -- A Model For Sustainable Conservation Of Threatened And Endangered Species, Mary Bomberger Brown, Mark E. Burbach, John Dinan, Renae J. Held, Ron J. Johnson, Joel G. Jorgensen, Jeanine Lackey, Jeffrey F. Marcus, Gina S. Matkin, Christine M. Thody Jan 2011

Nebraska's Tern And Plover Conservation Partnership -- A Model For Sustainable Conservation Of Threatened And Endangered Species, Mary Bomberger Brown, Mark E. Burbach, John Dinan, Renae J. Held, Ron J. Johnson, Joel G. Jorgensen, Jeanine Lackey, Jeffrey F. Marcus, Gina S. Matkin, Christine M. Thody

School of Natural Resources: Faculty Publications

Implementing successful conservation programs is critical if we are to protect the earth's most imperiled species. These programs must respect state and federal legal concerns as well as local economic and social interests, Here we describe a sustainable partnership approach to Piping Plover and Interior Least Tern conservation in Nebraska, USA. Partners include industry groups, federal, state, and local agencies, and non-governmental organizations. The factor that unifies all partners is a desire to accomplish cooperative threatened and endangered species conservation. We believe that implementing this sort of partnership model could be useful in addressing the protection of other species of …


Nest Survival Of Long-Billed Curlew In Nebraska, Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen Jan 2011

Nest Survival Of Long-Billed Curlew In Nebraska, Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen

School of Natural Resources: Faculty Publications

Long-billed Curlew Numenius americanus is an imperiled shorebird of western North America. Populations have declined dramatically in the last 150 years from the conversion of prairie to agriculture and it is now listed as a “Tier I at-risk” species in Nebraska. We undertook a 3-year project (2008–2010) to study the nest survival of Long-billed Curlews in Nebraska. We measured vegetation characteristics at each nest site (n = 14 nests) on two different spatial scales and used program MARK to model nest survival as a function of multiple covariates. Apparent nest survival was 29% (n = 4 successful nests) and our …


Estimates Of Duck Breeding Populations In The Nebraska Sandhills Using Double Observer Methodology, Mark P. Vrtiska, Larkin A. Powell Jan 2011

Estimates Of Duck Breeding Populations In The Nebraska Sandhills Using Double Observer Methodology, Mark P. Vrtiska, Larkin A. Powell

School of Natural Resources: Faculty Publications

The Nebraska Sandhills are an important area for breeding ducks in the Great Plains, but reliable estimates of breeding populations are unavailable. Double-observer methodology was used to estimate abundance of breeding duck populations in the Nebraska Sandhills. Aerial transect surveys were conducted using methodology similar to the cooperative Waterfowl Breeding Population and Habitat Survey conducted by the U.S. Fish and Wildlife Service and Canadian Wildlife Service. Observations by two front-seat observers and one rear-seat observer were used to account for incomplete detectability. Transect-specific population size and detection probabilities were estimated using program SURVIV; estimates were species-specific by type of social …